Cloudflare thinks something is wrong...

One of my clients has a Wordpress site that uses CloudFlare. They are complaining that CF keeps giving a "Error 524: A timeout occurred" which indicates that the server did not issue an HTTP response within their 100 second timeout period. I have not personally seen their site down at any point. I tried a little curl magic to test the response time and found it to be well under a single second using this:

That IP makes sure that the request is coming from my server and not using DNS to resolve back to CloudFlare. Of course, I could just be checking when everything is working perfectly.

So I have two questions. Should I add the "%T" LogFormat modifier to the Apache logs to see the connection time? And how should I go about watching my server resources to check for spikes that may be causing slow responses or downtime?

My gut is telling me this is a WP/DB access problem. They are using some plugins to do basic object caching. It looks like W3TC is one of them.

I'm trying to narrow down a bottle neck to this specific site. I can see a huge number of plugins in the plugins folder so I'm betting that this problem is site specific.

I just installed munin and got it running. I also installed monit and it is running, but I can't view it's page. I did open port 2812 in CSF, but I'm still getting Chrome's cannot connect error. Even though it is running, `netstat -tulpn` doesn't show it listening. I'm going to have dive into the logs and try to figure out what's going on with it.